Risk prediction in chest pain patients by biochemical markers including estimates of renal function

Background Early risk stratification of patients with chest pain may be improved by combining cardiac Troponin I (cTnI) results and ECG findings with markers of left-ventricular dysfunction, inflammation or renal function. Methods Serial measurements of cTnI were prospectively performed in 452 chest pain patients with a non-diagnostic ECG for AMI and admitted to the coronary care unit. NT-pro BNP, CRP, cystatin C and creatinine-clearance were retrospectively analyzed in admission samples. The prognostic value of these markers alone and in different combinations together with ECG findings was evaluated by multivariate logistic regression models. Results During follow-up, 14 deaths and 21 myocardial (re)-infarctions occurred. Independent predictors for the combined endpoint of death or (re)-infarction were peak cTnI ≥ 0.1 μg/L within 24 h (OR 3.9; 95% confidence interval [CI]1.5–10.4), cystatin C ≥ 1.28 mg/L (OR 5.6; 95% CI 1.9–16.3) and NT-pro BNP ≥ 550 ng/L (OR 2.7; 95% CI 1.0–7.3). At 2 h from admission, a combination of cTnI ≥ 0.1 μg/L, an abnormal ECG and NT-pro BNP or cystatin C as a third variable resulted in a similar stratification of patients to different risk groups. Conclusion cTnI, NT-pro BNP and cystatin C are strong risk predictors in patients with chest pain. For pragmatic reasons, a combination of cTnI ≥ 0.1 μg/L, ECG findings and a marker of renal function, preferably cystatin C, appears to be most appropriate for early risk stratification of these patients.